Is it safe to hang around predator magnets?

January 14, 2013

As male tungara frogs attract mates with their distinctive nighttime calls, they manage to beckon frog-eating bats and blood-sucking flies as well

As male tungara frogs attract mates with their distinctive nighttime calls, they manage to beckon frog-eating bats and blood-sucking flies as well. This risky reproductive behavior is well studied but researchers do not know if tungara calls influence the fate other frog species that share Central Panama's lowland streams.

A “collateral damage” hypothesis suggests other species, like Hyla ebraccata frogs, are at greater risk of predation, whereas the “shadow of safety” hypothesis suggests the opposite. Mallory Owens, a Butler University-STRI intern, ran visual and auditory experiments using model frogs and speakers that replicate tungara and ebraccata frog calls to address the question.

Owens is still analyzing the data but initial observations point to the collateral damage theory. Blood-sucking flies attracted by tungaras also swarm nearby Hyla ebraccata that would otherwise attract fewer bugs. These flies feed on frog blood and have the potential to spread blood-borne diseases.

Mallory's research has also piqued interest in studying tungaras in culverts or tire tracks, where they sometimes lay eggs. “They build nests that are not necessarily beneficial for offspring,” adding she is curious to study how nesting in human-created environments compares to nesting in natural sites.